1. Field of the Invention
The present invention relates to a waterproof device for a joint section, and more particularly to the waterproof device for a joint section which permits relative swinging between a pair of connected rods. It is effective to apply the present invention, for example, for waterproofing a joint section provided between a crank arm and a rod in a wiper device installed in a vehicle.
2. Related Art Statement
A typical wiper device for wiping a front glass of a car comprises a crank arm rotated by a motor, a connecting rod (hereinafter, referred to as a rod) for converting the rotation of the crank arm into reciprocative movement in a manner to reciprocate a linkage connected to a wiper arm, and a joint section, provided between the crank arm and the rod, which permits relative swinging between them.
In this type of wiper device, a waterproof device is mounted at the joint section between the crank arm and the rod as shown in FIG. 5. This waterproof device includes a seal member 7 integrally formed of an elastic material such as rubber. The seal member 7 is mounted to cover the joint section for waterproofing it. That is, one end 9 of the seal member 7 is fitted on the rod side of the joint section and the other end 8 thereof is slidably fitted on the crank arm end thereof.
Yet, this type of waterproof means for a joint section produces a partial gap between the seal member and the rod when thhe rod swings as shown in FIG. 5, because the seal member is slidably fitted on the crank arm end. It thus cannot serve as complete sealing.